We have CRM 2016 On-Premise. I am trying to run the default reports that comes with CRM and trying to build custom reports. But I am getting following error:

"Reporting Error: Error Details: Error occurred while fetching the list of data extensions installed on the report server."

Reporting service is running on the report server and also on CRM organization, the link is correct for the Report Server. 

There is nothing in the SQL Logs and also nothing in the CRM trace either. 

Please help!